The suicide bomber had detonated near a bus terminal when the Frontier Corps vehicle was passing by, Quetta police spokesperson Abid Mengal told Efe news. The Taliban claimed the attack in a statement.
"We accept responsibility of the suicide attack on Saryab Road, Quetta," Tehrik-e-Taliban Pakistan (TTP) spokesperson Mohamed Khurasani said.
The wounded included several members of the security forces.
Quetta, the capital of Balochistan province, is among the most conflict-ridden areas in Pakistan, with armed separatists, Taliban factions and terrorist groups operating in the region.
On November 9, a senior police official of the city was killed in an attack and six days later, a superintendent of police was shot dead, along with his wife, son and brother.
On Friday, two people were killed and another five were wounded in a suicide bomb attack against the vehicle of a senior police official in Peshawar.